/*
 * Driver for MMC and SSD cards for Cavium ThunderX SOCs.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2016 Cavium Inc.
 */
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/mmc/mmc.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pci.h>
#include "cavium.h"

static void thunder_mmc_acquire_bus(struct cvm_mmc_host *host)
{
        down(&host->mmc_serializer);
}

static void thunder_mmc_release_bus(struct cvm_mmc_host *host)
{
        up(&host->mmc_serializer);
}

static void thunder_mmc_int_enable(struct cvm_mmc_host *host, u64 val)
{
        writeq(val, host->base + MIO_EMM_INT(host));
        writeq(val, host->base + MIO_EMM_INT_EN_SET(host));
}

static int thunder_mmc_register_interrupts(struct cvm_mmc_host *host,
                                           struct pci_dev *pdev)
{
        int nvec, ret, i;

        nvec = pci_alloc_irq_vectors(pdev, 1, 9, PCI_IRQ_MSIX);
        if (nvec < 0)
                return nvec;

        /* register interrupts */
        for (i = 0; i < nvec; i++) {
                ret = devm_request_irq(&pdev->dev, pci_irq_vector(pdev, i),
                                       cvm_mmc_interrupt,
                                       0, cvm_mmc_irq_names[i], host);
                if (ret)
                        return ret;
        }
        return 0;
}

static int thunder_mmc_probe(struct pci_dev *pdev,
                             const struct pci_device_id *id)
{
        struct device_node *node = pdev->dev.of_node;
        struct device *dev = &pdev->dev;
        struct device_node *child_node;
        struct cvm_mmc_host *host;
        int ret, i = 0;

        host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
        if (!host)
                return -ENOMEM;

        pci_set_drvdata(pdev, host);
        ret = pcim_enable_device(pdev);
        if (ret)
                return ret;

        ret = pci_request_regions(pdev, KBUILD_MODNAME);
        if (ret)
                return ret;

        host->base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
        if (!host->base)
                return -EINVAL;

        /* On ThunderX these are identical */
        host->dma_base = host->base;

        host->reg_off = 0x2000;
        host->reg_off_dma = 0x160;

        host->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(host->clk))
                return PTR_ERR(host->clk);

        ret = clk_prepare_enable(host->clk);
        if (ret)
                return ret;
        host->sys_freq = clk_get_rate(host->clk);

        spin_lock_init(&host->irq_handler_lock);
        sema_init(&host->mmc_serializer, 1);

        host->dev = dev;
        host->acquire_bus = thunder_mmc_acquire_bus;
        host->release_bus = thunder_mmc_release_bus;
        host->int_enable = thunder_mmc_int_enable;

        host->use_sg = true;
        host->big_dma_addr = true;
        host->need_irq_handler_lock = true;
        host->last_slot = -1;

        ret = dma_set_mask(dev, DMA_BIT_MASK(48));
        if (ret)
                goto error;

        /*
         * Clear out any pending interrupts that may be left over from
         * bootloader. Writing 1 to the bits clears them.
         */
        writeq(127, host->base + MIO_EMM_INT_EN(host));
        writeq(3, host->base + MIO_EMM_DMA_INT_ENA_W1C(host));
        /* Clear DMA FIFO */
        writeq(BIT_ULL(16), host->base + MIO_EMM_DMA_FIFO_CFG(host));

        ret = thunder_mmc_register_interrupts(host, pdev);
        if (ret)
                goto error;

        for_each_child_of_node(node, child_node) {
                /*
                 * mmc_of_parse and devm* require one device per slot.
                 * Create a dummy device per slot and set the node pointer to
                 * the slot. The easiest way to get this is using
                 * of_platform_device_create.
                 */
                if (of_device_is_compatible(child_node, "mmc-slot")) {
                        host->slot_pdev[i] = of_platform_device_create(child_node, NULL,
                                                                       &pdev->dev);
                        if (!host->slot_pdev[i])
                                continue;

                        ret = cvm_mmc_of_slot_probe(&host->slot_pdev[i]->dev, host);
                        if (ret)
                                goto error;
                }
                i++;
        }
        dev_info(dev, "probed\n");
        return 0;

error:
        for (i = 0; i < CAVIUM_MAX_MMC; i++) {
                if (host->slot[i])
                        cvm_mmc_of_slot_remove(host->slot[i]);
                if (host->slot_pdev[i]) {
                        get_device(&host->slot_pdev[i]->dev);
                        of_platform_device_destroy(&host->slot_pdev[i]->dev, NULL);
                        put_device(&host->slot_pdev[i]->dev);
                }
        }
        clk_disable_unprepare(host->clk);
        return ret;
}

static void thunder_mmc_remove(struct pci_dev *pdev)
{
        struct cvm_mmc_host *host = pci_get_drvdata(pdev);
        u64 dma_cfg;
        int i;

        for (i = 0; i < CAVIUM_MAX_MMC; i++)
                if (host->slot[i])
                        cvm_mmc_of_slot_remove(host->slot[i]);

        dma_cfg = readq(host->dma_base + MIO_EMM_DMA_CFG(host));
        dma_cfg &= ~MIO_EMM_DMA_CFG_EN;
        writeq(dma_cfg, host->dma_base + MIO_EMM_DMA_CFG(host));

        clk_disable_unprepare(host->clk);
}

static const struct pci_device_id thunder_mmc_id_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa010) },
        { 0, }  /* end of table */
};

static struct pci_driver thunder_mmc_driver = {
        .name = KBUILD_MODNAME,
        .id_table = thunder_mmc_id_table,
        .probe = thunder_mmc_probe,
        .remove = thunder_mmc_remove,
};

module_pci_driver(thunder_mmc_driver);

MODULE_AUTHOR("Cavium Inc.");
MODULE_DESCRIPTION("Cavium ThunderX eMMC Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, thunder_mmc_id_table);